The present invention relates to an optical disk and optical disk processing apparatus, specifically a rewritable optical disk of which recording area is divided into a plurality of groups by annular boundaries, each of the above mentioned groups having a spare area having sectors which can be allocated in place of defective sectors of the disk, and an optical disk processing apparatus that is capable of recording and reproducing data from the optical disk.
The data zone format of the conventional optical disk will be described. FIG. 16 shows the data zone configuration of an optical disk described in xe2x80x9cSTANDARD ECMA-201, DATA INTERCHANGE ON 90 mm OPTICAL DISK CARTRIDGES.xe2x80x9d Although the standard relates to the fully read-only type, partially rewritable type, and fully rewritable type, the following description relates only to the fully rewritable type.
Referring to the figure, a data zone contains four defect management areas (DMAs). Two of them are placed before a user area, and the other two are placed after the user area. Buffer tracks are disposed on the radially inward side of the defect management area 1 and on the radially outward side of the defect management area 4. An area between the defect management area 2 and defect management area 3 is referred to as a user area, which forms a recording/reproducing area where user data is recorded or reproduced. Each defect management area contains a disk definition structure (DDS), a primary defect list (PDL), and a secondary defect list (SDL). DDS is recorded in the first sector of each DMA after the disk is initialized. The information stored there includes a code indicating the disk type of each group such as rewritable or read-only, and the first addresses of PDL and SDL. PDL contains the addresses of all defective sectors detected at initialization. SDL is placed immediately after PDL and contains the addresses of defective sectors and the addresses of replacement sectors for use in management of defective sectors detected at recording. PDL and SDL are defect (management) information for managing defective sectors in the optical disk. The sizes of PDL and SDL are determined by the length of the information stored therein. Identical PDLs and identical SDLs are recorded in the four defect management areas of the disk.
DMAs are placed at positions having the first address values predetermined on the disk. FIG. 17 shows the positions of DMAs on the conventional optical disk. The ECMA-201, which is explained as an example, specifies fixed values, as shown in FIG. 17.
The ISO/IEC 15041 standard regarding the same type of optical disk with different capacity defines a similar group configuration with two options of 512 bytes per sector and 2048 bytes per sector. FIG. 18A and FIG. 18B show the positions of DMAs on another type of conventional optical disk. As shown in FIG. 18A and FIG. 18B, the disk has fixed values which are different from the values of the example described earlier.
The drive apparatus that is capable of reproduction from the two types of disks described above incorporates information indicating the storage positions of DMAs of the disk types in its firmware.
The size of the spare area in each zone of these disks is substantially proportional to the size of the user area in the same zone. FIG. 19 shows the size of spare area of the conventional ECMA-201 optical disk. As shown in the figure, the number of spare tracks is determined so that the ratio of the number of spare tracks to the number of data tracks will not be smaller than 0.2%. The spare areas are located at the ends of the respective zones.
In the apparatus that drives the optical disk medium as described above, the position information sent from the host as a parameter of a read/write instruction is a logical address, and this must be converted into a physical address by the drive. In addition, the group configuration must be specified to identify the location of replacement sectors for defective sectors.
Because the conventional optical disks are configured as described above, it is necessary to add or modify the firmware of the optical disk apparatus that controls the conversion between physical addresses and logical addresses and the defect management which controls the allocation of spare areas when a medium having a different group configuration is introduced.
Also, the size of the defect management area for each group is fixed, and the sizes of defect management areas of a disk of a particular group configuration may be greater than necessary for some applications.
When a medium having a new group configuration is introduced, an optical disk apparatus which can be used only with the conventional group configuration is not capable of reproduction from the medium of the new group configuration because the information indicating the position of the area containing the position information of defective sectors and of the area storing the information indicating the group configuration cannot be obtained from the disk.
Since data is usually recorded from a zone including a sector having a lowest logical address, zones including sectors with lower logical addresses have higher probabilities of using the spare area. However, the sizes of spare areas in the different zones of the disk are substantially proportional to the sizes of the user areas in the zones. Accordingly, the error rates of data recorded in the zones of the disk are not uniform.
The zone including the sector having the lowest logical address value, e.g, value xe2x80x9c0xe2x80x9d, contains various control data and requires a higher reliability. But because the size of the spare area in each zone of the disk is substantially proportional to the size of the user area in the zone, the reliability of the control data is insufficient.
The present invention has been made to solve these problems. An object of the invention is to provide an optical disk that can be used for recording and reproduction without changing the firmware of the conventional apparatus even when the optical disk is introduced with a different group configuration. Another object is to provide an optical disk and optical disk processing apparatus that permits the size of a spare area to be changed as desired by means of application programs. A further object is to provide an optical disk that makes it easy to allocate the spare area according to the user access frequency and the degree of importance of the data to be recorded.
According one aspect of the invention, there is provided a rewritable optical disk of which recording area is divided into a plurality of groups by annular boundaries;
the number of sectors per track differing from one group to another,
said optical disk having a spare area provided for each of said groups and having sectors which can be allocated in place of defective sectors of the disk, and a user area in which the user is allowed to record and reproduce information;
said optical disk being configured so that
the ratio of the number of sectors in the spare area to the number of sectors in the user area in at least one of a group containing a sector having the lowest logical address value and a group containing a sector having the largest logical address is higher than the corresponding ratios in other groups.
With the above arrangement, the permissible number of defective sectors due to defect or contamination increases in the zone containing important descriptors of the logical format, and the degree of degradation of the descriptor read/write performance is reduced. Accordingly, an optical disk with high immunity to defect can be provided.
It may be so arranged that, among said other groups, groups having lower logical address values have greater ratios of the number of sectors in the spare area to the number of sectors in the user area.
With the above arrangement, the probability of read or write being impossible due to shortage of spare area is lower in a zone including sectors with lower logical addresses, where user data is recorded with higher probability. At the same time, this group structure can be represented by parameters, and recorded on the disk.
According to another aspect of the invention, there is provided a rewritable optical disk of which recording area is divided into a plurality of groups by annular boundaries; the number of sectors per track differing from one group to another, said optical disk having a spare area provided for each of said groups and having sectors which can be allocated in place of defective sectors of the disk; wherein
a read-only area contains a control data area that holds information for controlling recording/reproducing operation from said optical disk,
a rewritable area contains a plurality of defect management areas that hold information for controlling replacement of defective sectors, and
said control data area contains position information recorded to indicate the positions of said defect management areas.
With the above arrangement, the position information indicating the position of the defect management area is recorded in the control data area provided in a read-only area, and the defect management area in a rewritable area can be accessed by reading the above-mentioned position information. Accordingly, the optical disk apparatus that drives this optical disk is capable of recording or reproduction from the optical disk even if it is not informed of the information related to the layout of the defect management area of the optical disk beforehand.
Even when the optical disk format is modified or added, an apparatus manufactured earlier can be used with the new optical disk. Accordingly, the compatibility of optical disks is significantly enhanced.
It may be so arranged that said position information includes information indicating the start positions, number, or sizes of said defect management areas.
With the above configuration, apparatus manufactured before the changes in or addition of the format can be used despite the changes in such information. The range of allowable format changes and additions greatly increases.
It may be so arranged that the start position of said control data area is always set to a fixed position, irrespective of the recording capacity of the optical disk.
With the above arrangement, it is possible to implement a drive apparatus that can easily record and reproduce data from optical disks with different group structures or capacities.
According to another aspect of the invention, there is provided a rewritable optical disk of which recording area is divided into a plurality of groups by annular boundaries; the number of sectors per track differing from one group to another, said optical disk having a spare area provided for each of said groups and having sectors which can be allocated in place of defective sectors of the disk; wherein
a read-only area contains a control data area that holds information for controlling recording/reproducing operation from said optical disk, and
a rewritable area contains a plurality of defect management areas that hold information for controlling replacement of defective sectors,
wherein said defect management area contains information indicating the first address or size of said spare area.
With the above arrangement, it is possible to obtain all information of the layout of the spare areas from the optical disk and allows the spare areas to be freely configured to suit the use.
The address and size of each spare area can be treated as equivalent information when the spare areas are located at the ends of the respective zones.
According another aspect of the invention, there is provided an optical disk processing apparatus for handling a rewritable optical disk of which recording area is divided into a plurality of groups by annular boundaries; the number of sectors per track differing from one group to another, said optical disk having a spare area provided for each of said groups and having sectors which can be allocated in place of defective sectors of the disk; wherein
a read-only area contains a control data area that holds information for controlling recording/reproducing operation from said optical disk,
a rewritable area contains a plurality of defect management areas that hold information for controlling replacement of defective sectors,
wherein said optical disk processing apparatus specifying the size of said spare area at initialization of said optical disk and recording the specified size or the first address of the spare area in said defect management area.
With the above arrangement, the optical disk processing apparatus can set the size of the spare area as desired at initialization. This setting can be held on the optical disk and can be freely changed at initialization. Since the size of the spare area can be changed as required, the user and application program can determine the size of the spare area when the disk is formatted. Moreover, a unique defect management method can be built, for instance, to perform defect management just by slip processing rather than by replacement, by specifying the size of the spare area to 0, that is, maximizing the user area. A flexible format can be built for use with a variety of optical disks which may be introduced in the future.
According to another aspect of the invention, there is provided an optical disk drive apparatus operable to read and/or write data in user areas of an optical disk, and to use spare areas in place of user areas in case of defects in the user areas, the disk drive apparatus being operable to read from a disk information from which the position and size of spare areas can be determined.
With the above arrangement, it is possible to determine the position and size of the spare area based on the information read from the optical disk.
According to another aspect of the invention, there is provided a rewritable optical disk of which recording area is divided into a plurality of groups by annular boundaries;
the number of sectors per track differing from one group to another,
said optical disk having
a read-only area containing a control data area that holds information for controlling recording/reproducing operation from said optical disk,
wherein said control data area contains a parameter expressing a linear function of group number for obtaining the number of tracks in a given group or a linear function of group number for obtaining the number of sectors in a given group.
With the above arrangement, the number of tracks in particular groups or the number of sectors per track is a linear function of group number. The zone configuration is identified by using the constant of this function as information indicating the group structure. Accordingly, the disk allows the zone configuration to be identified from fewer parameters than a disk having a table of the numbers of sectors for the respective zones. In addition, by maintaining linear relationships for all parameters determining the zone configuration of the optical disk, the firmware routine of the optical disk drive apparatus can be simplified.
According to a further aspect of the invention, there is provided a rewritable optical disk of which recording area is divided into a plurality of groups by annular boundaries;
the number of sectors per track differing from one group to another,
said optical disk having
a read-only area containing a control data area that holds information for controlling recording/reproducing operation from said optical disk,
wherein
said defect management area contains information for obtaining the number of sectors in the spare area of a given group.
With the above arrangement, the number of spare area sectors in particular groups can be obtained by the use of the information stored in the defect management area. This disk enables the group structure to be identified with a smaller amount of information.
It may be so arranged that said information comprises a parameter of a linear or quadratic function of group number for obtaining the number of sectors in the spare area of said given group.
With the above arrangement, the number of spare area sectors in particular groups is a linear or quadratic function of group number. The number of spare area sectors in each group can be known by using constants of the function as information indicating the group configuration. This disk enables the group structure to be identified with a smaller amount of information than the disk having a table of the numbers of sectors for the respective zones. In addition, by maintaining linear relationships for all parameters determining the number of spare area sectors in the optical disk, the firmware routine of the optical disk drive apparatus can be simplified.
It may be so arranged that said information comprises a ratio of the number of sectors belonging to the spare area to the total number of sectors.
With the above arrangement, the number of sectors in the spare area of particular groups is proportional to the number of sectors in the same group, and the ratio is recorded in the area having the position information of the spare area of each group, so that the zone configuration can be identified with a smaller amount of information than when the firmware of the optical disk drive apparatus uses tables of the size or position of the spare area.
Even when the optical disk drive apparatus drives an optical disk having an unknown disk group structure, the data can be recorded and reproduced by using the position information of the spare area.